A dual-axis rotation rule for updating the head direction cell reference frame during movement in three dimensions

In the mammalian brain, allocentric (Earth-referenced) head direction, called azimuth, is encoded by head direction (HD) cells, which fire according to the facing direction of the animal’s head. On a horizontal surface, rotations of the head around the dorsoventral (D-V) axis, called yaw, correspond to changes in azimuth and elicit appropriate updating of the HD “compass” signal to enable large-scale navigation. However, if the animal moves through three-dimensional (3D) space then there is no longer a simple relationship between yaw rotations and azimuth changes, and so processing of 3D rotations is needed. Construction of a global 3D compass would require complex integration of 3D rotations, and also a large neuronal population, most neurons of which would be silent most of the time since animals rarely sample all available 3D orientations. We propose that, instead, the HD system treats the 3D space as a set of interrelated 2D surfaces. It could do this by updating activity according to both yaw rotations around the D-V axis and rotations of the D-V axis around the gravity-defined vertical axis. We present preliminary data to suggest that this rule operates when rats move between walls of opposing orientations. This dual-axis rule, which we show is straightforward to implement using the classic one-dimensional “attractor” architecture, allows consistent representation of azimuth even in volumetric space and thus may be a general feature of mammalian directional computations even for animals that swim or fly.NEW & NOTEWORTHY Maintaining a sense of direction is complicated when moving in three-dimensional (3D) space. Head direction cells, which update the direction sense based on head rotations, may accommodate 3D movement by processing both rotations of the head around the axis of the animal’s body and rotations of the head/body around gravity. With modeling we show that this dual-axis rule works in principle, and we present preliminary data to support its operation in rats.

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A proposed rule for updating of the head direction cell reference frame following rotations in three dimensions

10.1101/043711 ◽

2016 ◽

Cited By ~ 6

Author(s):

Jonathan Wilson ◽

Hector Page ◽

Kate Jeffery

Keyword(s):

Reference Frame ◽

Vertical Axis ◽

Vestibular Nuclei ◽

Three Dimensions ◽

Mammalian Brain ◽

Head Direction ◽

Heading Direction ◽

Vertical Walls ◽

Sloping Surface ◽

Axis Rotation

In the mammalian brain, allocentric (Earth-referenced) heading direction, called azimuth, is encoded by head direction (HD) cells, which fire according to the facing direction of the rat's head. If the animal is on a horizontal surface then egocentric (self-referenced) rotations of the head around the dorso-ventral axis, called yaw, correspond to changes in azimuth, and elicit appropriate updating of the HD signal. However, if the surface is sloping steeply then yaw rotations no longer map linearly to changes in azimuth. The brain could solve this problem simply by always firing according to direction on the local (sloping) surface instead; however, if the animal moves between surfaces having different compass orientations then errors would accumulate in the subsequent azimuth signal. These errors could be avoided if the HD system instead combines two updating rules: yaw rotations around the D-V axis and rotations of the D-V axis around the gravity-defined vertical axis. We show here that when rats move between vertical walls of different orientations then HD cells indeed rotate their activity by an amount corresponding to the amount of vertical-axis rotation. With modelling, we then show how this reference-frame rotation, which may be driven by inputs from the vestibular nuclei or vestibulocerebellum, allows animals to maintain a simple yaw-based updating rule while on a given plane, but also to avoid accumulation of heading errors when moving between planes.

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Three-dimensional tuning of head direction cells in rats

Journal of Neurophysiology ◽

10.1152/jn.00880.2017 ◽

2019 ◽

Vol 121 (1) ◽

pp. 4-37 ◽

Cited By ~ 16

Author(s):

Michael E. Shinder ◽

Jeffrey S. Taube

Keyword(s):

Horizontal Plane ◽

Reference Frames ◽

Three Dimensional ◽

Vertical Axis ◽

Ventral Surface ◽

Three Dimensions ◽

Head Direction ◽

Horizontal Canal ◽

Cell Responses ◽

The Earth

Head direction (HD) cells fire when the animal faces that cell’s preferred firing direction (PFD) in the horizontal plane. The PFD response when the animal is oriented outside the earth-horizontal plane could result from cells representing direction in the plane of locomotion or as a three-dimensional (3D), global-referenced direction anchored to gravity. To investigate these possibilities, anterodorsal thalamic HD cells were recorded from restrained rats while they were passively positioned in various 3D orientations. Cell responses were unaffected by pitch or roll up to ~90° from the horizontal plane. Firing was disrupted once the animal was oriented >90° away from the horizontal plane and during inversion. When rolling the animal around the earth-vertical axis, cells were active when the animal’s ventral surface faced the cell’s PFD. However, with the rat rolled 90° in an ear-down orientation, pitching the rat and rotating it around the vertical axis did not produce directionally tuned responses. Complex movements involving combinations of yaw-roll, but usually not yaw-pitch, resulted in reduced directional tuning even at the final upright orientation when the rat had full visual view of its environment and was pointing in the cell’s PFD. Directional firing was restored when the rat’s head was moved back-and-forth. There was limited evidence indicating that cells contained conjunctive firing with pitch or roll positions. These findings suggest that the brain’s representation of directional heading is derived primarily from horizontal canal information and that the HD signal is a 3D gravity-referenced signal anchored to a direction in the horizontal plane. NEW & NOTEWORTHY This study monitored head direction cell responses from rats in three dimensions using a series of manipulations that involved yaw, pitch, roll, or a combination of these rotations. Results showed that head direction responses are consistent with the use of two reference frames simultaneously: one defined by the surrounding environment using primarily visual landmarks and a second defined by the earth’s gravity vector.

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A biomimetic 3D airflow sensor made of an array of two piezoelectric metal-core fibers

Sensor Review ◽

10.1108/sr-12-2016-0278 ◽

2017 ◽

Vol 37 (3) ◽

pp. 312-321 ◽

Cited By ~ 1

Author(s):

Yixiang Bian ◽

Can He ◽

Kaixuan Sun ◽

Longchao Dai ◽

Hui Shen ◽

...

Keyword(s):

Design Methodology ◽

Spherical Surface ◽

Three Dimensional ◽

Three Dimensions ◽

Piezoceramic Cylinder ◽

Metal Core ◽

Content Type ◽

3D Space ◽

Highly Sensitive ◽

Airflow Sensor

Purpose The purpose of this paper is to design and fabricate a three-dimensional (3D) bionic airflow sensing array made of two multi-electrode piezoelectric metal-core fibers (MPMFs), inspired by the structure of a cricket’s highly sensitive airflow receptor (consisting of two cerci). Design/methodology/approach A metal core was positioned at the center of an MPMF and surrounded by a hollow piezoceramic cylinder. Four thin metal films were spray-coated symmetrically on the surface of the fiber that could be used as two pairs of sensor electrodes. Findings In 3D space, four output signals of the two MPMFs arrays can form three “8”-shaped spheres. Similarly, the sensing signals for the same airflow are located on a spherical surface. Originality/value Two MPMF arrays are sufficient to detect the speed and direction of airflow in all three dimensions.

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Synthetic reflection seismograms in three dimensions by a locked‐mode approximation

Geophysics ◽

10.1190/1.1442660 ◽

1989 ◽

Vol 54 (3) ◽

pp. 350-358 ◽

Cited By ~ 24

Author(s):

G. Nolet ◽

R. Sleeman ◽

V. Nijhof ◽

B. L. N. Kennett

Keyword(s):

Finite Difference ◽

Born Approximation ◽

Large Scale ◽

Layered Medium ◽

Three Dimensional ◽

Simple Algorithm ◽

Realistic Model ◽

Three Dimensions ◽

Acoustic Response ◽

Many Sources

We present a simple algorithm for computing the acoustic response of a layered structure containing three‐dimensional (3-D) irregularities, using a locked‐mode approach and the Born approximation. The effects of anelasticity are incorporated by use of Rayleigh’s principle. The method is particularly attractive at somewhat larger offsets, but computations for near‐source offsets are stable as well, due to the introduction of anelastic damping. Calculations can be done on small minicomputers. The algorithm developed in this paper can be used to calculate the response of complicated models in three dimensions. It is more efficient than any other method whenever many sources are involved. The results are useful for modeling, as well as for generating test signals for data processing with realistic, model‐induced “noise.” Also, this approach provides an alternative to 2-D finite‐difference calculations that is efficient enough for application to large‐scale inverse problems. The method is illustrated by application to a simple 3-D structure in a layered medium.

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Gold Exploration in Two and Three Dimensions: Improved and Correlative Insights from Microscopy and X-Ray Computed Tomography

Minerals ◽

10.3390/min10050476 ◽

2020 ◽

Vol 10 (5) ◽

pp. 476

Author(s):

Joshua Chisambi ◽

Bjorn von der Heyden ◽

Muofhe Tshibalanganda ◽

Stephan Le Roux

Keyword(s):

Computed Tomography ◽

Spatial Distribution ◽

Gold Mineralization ◽

Three Dimensional ◽

Three Dimensions ◽

Low Grade ◽

X Ray ◽

3D Space ◽

X Ray Computed ◽

2D And 3D

In this contribution, we highlight a correlative approach in which three-dimensional structural/positional data are combined with two dimensional chemical and mineralogical data to understand a complex orogenic gold mineralization system; we use the Kirk Range (southern Malawi) as a case study. Three dimensional structures and semi-quantitative mineral distributions were evaluated using X-ray Computed Tomography (XCT) and this was augmented with textural, mineralogical and chemical imaging using Scanning Electron Microscopy (SEM) and optical microscopy as well as fire assay. Our results detail the utility of the correlative approach both for quantifying gold concentrations in core samples (which is often nuggety and may thus be misrepresented by quarter- or half-core assays), and for understanding the spatial distribution of gold and associated structures and microstructures in 3D space. This approach overlays complementary datasets from 2D and 3D analytical protocols, thereby allowing a better and more comprehensive understanding on the distribution and structures controlling gold mineralization. Combining 3D XCT analyses with conventional 2D microscopies derive the full value out of a given exploration drilling program and it provides an excellent tool for understanding gold mineralization. Understanding the spatial distribution of gold and associated structures and microstructures in 3D space holds vast potential for exploration practitioners, especially if the correlative approach can be automated and if the resultant spatially-constrained microstructural information can be fed directly into commercially available geological modelling software. The extra layers of information provided by using correlative 2D and 3D microscopies offer an exciting new tool to enhance and optimize mineral exploration workflows, given that modern exploration efforts are targeting increasingly complex and low-grade ore deposits.

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Large-scale numerical simulations: Convection in an annular channel rotating about a vertical axis with side-walls

Proceedings of the International Astronomical Union ◽

10.1017/s1743921308022564 ◽

2008 ◽

Vol 4 (S252) ◽

pp. 111-112

Author(s):

Yingli Chang ◽

Yu Liu

Keyword(s):

Large Scale ◽

Fluid Dynamic ◽

Three Dimensional ◽

Annular Channel ◽

Vertical Axis ◽

Jet Flows ◽

Nonlinear Convection ◽

Strongly Nonlinear ◽

Convection Model ◽

Side Walls

AbstractFor the purpose of understanding the dynamics of planetary atmospheres, we use the annular convection model to simulate the dynamics of atmospheres of Jupiter and Saturn. The model (annular channel) rotates about a vertical axis with side-walls, and it is heated from below.We use the software NaSt3DGP (a parallel software package to solve the 3D incompressible fluid dynamic problems in Cartesian coordinates by using Finite Difference Method) for the computation. It's reliability is tested by our application to simulate fully three-dimensional nonlinear convection in a box with lateral stress-free side-walls, uniformly heated from below. We found that, at moderately large Rayleigh numbers, the complex formation of multiple-jet flows can be maintained by the traveling convective eddies; we also found that the type of the sidewall velocity condition does not play an essential role in determining the primary properties of strongly nonlinear convection.

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A platform for brain-wide imaging and reconstruction of individual neurons

eLife ◽

10.7554/elife.10566 ◽

2016 ◽

Vol 5 ◽

Cited By ~ 192

Author(s):

Michael N Economo ◽

Nathan G Clack ◽

Luke D Lavis ◽

Charles R Gerfen ◽

Karel Svoboda ◽

...

Keyword(s):

Long Range ◽

High Speed ◽

Large Scale ◽

Three Dimensional ◽

Image Data ◽

Mammalian Brain ◽

Projection Neurons ◽

Computational Tools ◽

Two Photon ◽

Axonal Arbors

The structure of axonal arbors controls how signals from individual neurons are routed within the mammalian brain. However, the arbors of very few long-range projection neurons have been reconstructed in their entirety, as axons with diameters as small as 100 nm arborize in target regions dispersed over many millimeters of tissue. We introduce a platform for high-resolution, three-dimensional fluorescence imaging of complete tissue volumes that enables the visualization and reconstruction of long-range axonal arbors. This platform relies on a high-speed two-photon microscope integrated with a tissue vibratome and a suite of computational tools for large-scale image data. We demonstrate the power of this approach by reconstructing the axonal arbors of multiple neurons in the motor cortex across a single mouse brain.

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Time-Resolved Experimental Characterization of the Wakes Shed by H-Shaped and Troposkien Vertical Axis Wind Turbines

Journal of Energy Resources Technology ◽

10.1115/1.4035907 ◽

2017 ◽

Vol 139 (3) ◽

Cited By ~ 14

Author(s):

Giacomo Persico ◽

Vincenzo Dossena ◽

Berardo Paradiso ◽

Lorenzo Battisti ◽

Alessandra Brighenti ◽

...

Keyword(s):

Wind Turbines ◽

Large Scale ◽

Three Dimensional ◽

Vertical Axis ◽

Speed Ratio ◽

Local Dynamic ◽

Performance Measurements ◽

Time Resolved ◽

Vertical Axis Wind Turbines ◽

Blade Section

In this paper, the aerodynamics of two vertical axis wind turbines (VAWTs) are discussed, on the basis of a wide set of experiments performed at Politecnico di Milano, Milan, Italy. A H-shaped and a Troposkien Darrieus turbine for microgeneration, featuring the same swept area and blade section, are tested at full-scale. Performance measurements show that the Troposkien rotor outperforms the H-shaped turbine, thanks to the larger midspan section of the Troposkien rotor and to the nonaerodynamic struts of the H-shaped rotor. These features are consistent with the character of the wakes shed by the turbines, measured by means of hot wire anemometry on several surfaces downstream of the models. The H-shape and Troposkien turbine wakes exhibit relevant differences in the three-dimensional morphology and unsteady evolution. In particular, large-scale vortices dominate the tip region of the wake shed by the H-shape turbine; these vortices pulsate significantly during the period, due to the periodic fluctuation of the blade aerodynamic loading. Conversely, the highly tapered shape of the Troposkien rotor not only prevents the onset of tip vortices, but also induces a dramatic spanwise reduction of tip speed ratio (TSR), promoting the onset of local dynamic stall marked by high periodic and turbulent unsteadiness in the tip region of the wake. The way in which these mechanisms affect the wake evolution and mixing process for the two classes of turbines is investigated for different tip speed ratios, highlighting some relevant implications in the framework of wind energy exploitation.

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Development of three-dimensional wetting and drying algorithm for the Geophysical Scale Transport Multi-Block Hydrodynamic Sediment and Water Quality Transport Modeling System (GSMB)

10.21079/11681/41085 ◽

2021 ◽

Author(s):

Ray Chapman ◽

Phu Luong ◽

Sung-Chan Kim ◽

Earl Hayter

Keyword(s):

Water Quality ◽

Water Wave ◽

Large Scale ◽

Three Dimensional ◽

The United States ◽

Technical Note ◽

Three Dimensions ◽

Transport Modeling ◽

Two Dimensional ◽

Wetting And Drying

The Environmental Laboratory (EL) and the Coastal and Hydraulics Laboratory (CHL) have jointly completed a number of large-scale hydrodynamic, sediment and water quality transport studies. EL and CHL have successfully executed these studies utilizing the Geophysical Scale Transport Modeling System (GSMB). The model framework of GSMB is composed of multiple process models as shown in Figure 1. Figure 1 shows that the United States Army Corps of Engineers (USACE) accepted wave, hydrodynamic, sediment and water quality transport models are directly and indirectly linked within the GSMB framework. The components of GSMB are the two-dimensional (2D) deep-water wave action model (WAM) (Komen et al. 1994, Jensen et al. 2012), data from meteorological model (MET) (e.g., Saha et al. 2010 - http://journals.ametsoc.org/doi/pdf/10.1175/2010BAMS3001.1), shallow water wave models (STWAVE) (Smith et al. 1999), Coastal Modeling System wave (CMS-WAVE) (Lin et al. 2008), the large-scale, unstructured two-dimensional Advanced Circulation (2D ADCIRC) hydrodynamic model (http://www.adcirc.org), and the regional scale models, Curvilinear Hydrodynamics in three dimensions-Multi-Block (CH3D-MB) (Luong and Chapman 2009), which is the multi-block (MB) version of Curvilinear Hydrodynamics in three-dimensions-Waterways Experiments Station (CH3D-WES) (Chapman et al. 1996, Chapman et al. 2009), MB CH3D-SEDZLJ sediment transport model (Hayter et al. 2012), and CE-QUAL Management - ICM water quality model (Bunch et al. 2003, Cerco and Cole 1994). Task 1 of the DOER project, “Modeling Transport in Wetting/Drying and Vegetated Regions,” is to implement and test three-dimensional (3D) wetting and drying (W/D) within GSMB. This technical note describes the methods and results of Task 1. The original W/D routines were restricted to a single vertical layer or depth-averaged simulations. In order to retain the required 3D or multi-layer capability of MB-CH3D, a multi-block version with variable block layers was developed (Chapman and Luong 2009). This approach requires a combination of grid decomposition, MB, and Message Passing Interface (MPI) communication (Snir et al. 1998). The MB single layer W/D has demonstrated itself as an effective tool in hyper-tide environments, such as Cook Inlet, Alaska (Hayter et al. 2012). The code modifications, implementation, and testing of a fully 3D W/D are described in the following sections of this technical note.

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A THREE-DIMENSIONAL SIMULATION AND VISUALIZATION SYSTEM FOR UAV PHOTOGRAMMETRY

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-2-w6-217-2017 ◽

2017 ◽

Vol XLII-2/W6 ◽

pp. 217-222 ◽

Cited By ~ 3

Author(s):

Y. Liang ◽

Y. Qu ◽

T. Cui

Keyword(s):

Large Scale ◽

Three Dimensional ◽

Cost Effective ◽

Three Dimensions ◽

Wind Condition ◽

Plan Evaluation ◽

Visualization System ◽

Flight Plan ◽

Aerial Photogrammetry ◽

Dimensional Simulation

Nowadays UAVs has been widely used for large-scale surveying and mapping. Compared with manned aircraft, UAVs are more cost-effective and responsive. However, UAVs are usually more sensitive to wind condition, which greatly influences their positions and orientations. The flight height of a UAV is relative low, and the relief of the terrain may result in serious occlusions. Moreover, the observations acquired by the Position and Orientation System (POS) are usually less accurate than those acquired in manned aerial photogrammetry. All of these factors bring in uncertainties to UAV photogrammetry. To investigate these uncertainties, a three-dimensional simulation and visualization system has been developed. The system is demonstrated with flight plan evaluation, image matching, POS-supported direct georeferencing, and ortho-mosaicing. Experimental results show that the presented system is effective for flight plan evaluation. The generated image pairs are accurate and false matches can be effectively filtered. The presented system dynamically visualizes the results of direct georeferencing in three-dimensions, which is informative and effective for real-time target tracking and positioning. The dynamically generated orthomosaic can be used in emergency applications. The presented system has also been used for teaching theories and applications of UAV photogrammetry.

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